Abstract
The mechanisms by which various DNA glycosylases initiate the base excision repair pathways are discussed. Fundamental distinctions are made between "simple glycosylases," that do not form DNA single-strand breaks, and "glycosylases/abasic site lyases," that do form single-strand breaks. Several groupings of BER substrate sites are defined and some interactions between these groupings and glycosylase mechanisms discussed. Two characteristics are proposed to be common among all BER glycosylases: a nucleotide flipping step that serves to expose the scissile glycosyl bond to catalysis, and a glycosylase transition state characterized by substantial tetrahedral character at the base glycosyl atom.
Original language | English (US) |
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Pages (from-to) | 678-682 |
Number of pages | 5 |
Journal | Free Radical Biology and Medicine |
Volume | 32 |
Issue number | 8 |
DOIs | |
State | Published - Apr 15 2002 |
Externally published | Yes |
Keywords
- Base flipping
- DNA glycosylases
- Free radical
- Nucleotide flipping
ASJC Scopus subject areas
- Biochemistry
- Physiology (medical)